A terminal connection structure of a conventional example is shown in FIGS. 1 and 2. In FIGS. 1 and 2, a wire W includes a conductor 50 and an insulating coating 51 that covers an outer periphery of the conductor 50. At an end of the wire W, the insulating coating 51 is peeled to expose the conductor 50. A terminal 60 is connected to the exposed conductor 50.
The terminal 60 includes a wire crimping section 61 and an external connection section 62. The wire crimping section 61 includes a base section 61a and a pair of caulking sections 61b formed in extension from opposite edges of the base section 61a. By caulking the pair of caulking sections 61b, the conductor 50 is fixed to the wire crimping section 61 by a crimping force thereof.
A terminal connection structure of another conventional example (see Patent Literature 1) is shown in FIGS. 3 and 4. In FIGS. 3 and 4(a), a terminal 70 includes a wire crimping section 71 and an external connection section 72. The wire crimping section 71 includes a base section 71a and a pair of caulking sections 71b formed in extension from opposite edges of the base section 71a. By caulking the pair of caulking sections 71b, a conductor 50 is fixed to the wire crimping section 71 by a crimping force thereof.
Furthermore, the conductor 50 and the pair of caulking sections 71b have a friction-agitation connection section 73 formed by making these sections into a state of integrated plastic flow. The friction-agitation connection section 73 is formed by using a connection tool (not shown) having a pin at the tip of a shoulder and operating the connection tool from the side of the pair of caulking sections 71b. 